The present disclosure relates to a generator, and more particularly to an internal oil management system for a starter-generator.
Aircraft powered by gas turbine engines often include a mechanically driven accessory gearbox which connects to accessory systems such as an electrical starter-generator or electric generator.
High power density aircraft generators utilize an internal oil management system. The internal oil management system provides supplemental cooling to the generator main stator through a back iron oil flow which is defined by oil grooves formed within the stator housing. As the main stator is typically constructed as a stack of adhesively bonded laminations, a main stator sleeve is typically mounted between the lamination stack and the oil cooling grooves to ensure oil does not leak through the lamination stack into the generator air gap thus increasing generator losses due to viscous shear of oil within the generator air gap.
The main stator sleeve is typically constructed from bar or tube stock which is machined on an inner diameter to closely fit onto the main stator core. The outer diameter of the main stator sleeve is then machined after installation onto the main stator core to assure a close fit with the oil grooves. Although effective, such machining is relatively significant as machining is required prior and subsequent to main stator core assembly.